Cosmetic Composition Containing Novel Fractal Particle-Based Gels

ABSTRACT

A method of instantly reducing the appearance of wrinkles and skin imperfections while smoothing the skin, which comprises applying a cosmetic composition comprising a fractal particle based gel.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority to, U.S.patent application Ser. No. 11/643,583 filed on Dec. 21, 2006, theentirety of which is herein incorporated by reference for all purposes.

FIELD OF THE INVENTION

The present invention relates to cosmetic compositions and moreparticularly, to cosmetic compositions with space filling effects forimproved surface appearance of biologic substrates such as skin andlips.

BACKGROUND OF THE INVENTION

A number of methods have been developed to reduce wrinkles and minimizefine lines. Some of these methods include active ingredients such asantioxidants; agents that act by neurotransmission inhibition in nervecells such as botulinum toxin (Botox™) (Allergan, Irvine, Calif.),thereby relaxing contracted muscles; agents that accelerate the cellrenewal process such as hydroxy and fruit acids like retinoic acid;emollients such as shea butter; skin plumpers such as hyaluronic acid;fillers such as collagen; light-diffusing pigments and microsphereswhich create the illusion that wrinkles have disappeared. Other methodshave been developed to reduce the appearance of pores, skin surfaceunevenness and imperfections and the like. Some of these methods includeskin lightening agents, and filling and camouflaging the skin.

Unfortunately, many cosmetic foundations and make-ups actuallyaccentuate wrinkles and fine lines due to migration of the pigments intothe wrinkle crevices. Other products cover the skin imperfections butcreate an unnatural, caked-on appearance. Others, such as mica, reflectrather than diffuse and scatter light, thereby resulting in a shinyappearance. Additionally, some of these methods are not immediate,requiring days and weeks of continued use to see effects. Others areinvasive, requiring injections, patient discomfort, and may entailredness, swelling and other side effects.

Foundations in the form of oil-in-water emulsions that cover the skinare well known. However, foundations that provide high coveragetypically result in an unnatural, caked on appearance. Moreover, highpigment loadings in these types of foundations tend to crease andmigrate over time.

The inventors have discovered that fractal particle gels containing arefractive index matching polymer (as herein described) can beincorporated into a cosmetic formulation, which, when applied to abiologic substrate such as skin or lips, creates a film that is spacefilling to effect smooth skin surfaces and thus conceal fine lines andwrinkles to mitigate the aforementioned disadvantages of the prior artformulations.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide cosmeticcompositions comprising a fractal gel network of oppositely chargednanoparticles, to achieve space filling for smoothing applicationsurfaces.

It is another object of the present invention to provide a cosmeticcomposition containing a gel network comprised of two or more types ofsubmicron sized fractal particles having opposite surface charges (zetapotential) at a given pH.

It is yet another object of the present invention to provide a cosmeticcomposition comprising a cosmetically suitable medium, such as aqueous,nonaqueous, water-in-oil, and oil-in-water emulsions, containing afractal gel.

In another aspect of the invention the compositions are suitable as hairtreatment products, especially as mascaras to treat thinning hair, inlight of the porous, reticulated structure, which provides a volumizingbenefit the hair shaft.

It is a further object of the present invention to provide a cosmeticcomposition having unique space filling properties to topographicallysmooth lines and wrinkles of the skin surface.

It is yet another object of the present invention to provide a cosmeticcomposition comprising a fractal gel primer composition to provide asmooth surface for use with a topcoat cosmetic composition, wherein theapplication and look of the topcoat composition applied on top of theprimer composition is enhanced due to the smoothing effect of thefractal gel network present in the primer composition layer.

Further according to this and other objects and advantages of thepresent invention are provided methods for filling wrinkles, fine lines,pores, skin surface unevenness and imperfections while providing asurface smoothing effect by space filling via a gel network. The methodincludes layering a smoothing layer onto the skin in conjunction with atopcoat pigmented layer to make the skin appear to be light releasingand brighter.

In another aspect of the invention, the present invention is applicableto human skin in any cosmetically acceptable vehicle.

These novel features of the present invention will become apparent tothose skilled in the art from the following detailed description, whichis simply, by way of illustration, various modes contemplated forcarrying out the invention. As will be realized, the invention iscapable of additional, different obvious aspects, all without departingfrom the invention. Accordingly, the Figures and specification areillustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a graphical plot of the zeta potential of various metal oxidesas a function of pH.

FIG. 2 depicts the formation of a gel network from aqueous dispersionsof alumina and silica.

FIG. 3 depicts the rough surface created by fine lines and wrinkles thattraps light, exacerbating topological features.

FIG. 4 depicts the smoothing gel layer on top of the rough skin surface.

FIG. 5 depicts the smoothing gel layer when used as a primer forpigmented cosmetics normalized with respect to the opticalcharacteristics of the cosmetic composition.

DETAILED DESCRIPTION OF THE INVENTION

The cosmetic composition of the present invention comprises (i) afractal particle based gel (“fractal gel”) comprising a first fractalparticle and a second fractal particle, the first and second fractalparticles having opposite net surface charges (zeta potential.

The fractal particle gel network has an open, reticulated structure,with size domains and refractive indices for the fractal particlesadapted to effectively fill wrinkles and other surface imperfections inthe skin, thus providing a surface smoothing effect to the skin.Accordingly, when applied to skin, the cosmetic composition provides anatural, smooth and youthful appearance with visible reduction inwrinkles and skin imperfections. The open structure of the fractal gelmatrix thus fills the wrinkles with a film of significantly lowerpacking density that minimizes and even avoids the undesirable chalkyappearance of conventional cosmetic products. Moreover, the openstructure of the gel matix provides significant surface area for sebumabsorption, thus improving wear for the cosmetic composition, andwithout the extensive use of film formers.

Another beneficial aspect of the invention is the ability of the fractalparticle gel network to display unique rheological properties, which areespecially useful in cosmetic applications. The gel network is highlythixotropic. That is to say, the viscosity of the gel rapidly diminishesunder increasing shear stress, yet the gel network reforms quickly oncethe shear stress is removed. Effectively, this imparts an effect whereinthe composition transforms from viscous, non-flowing compositions to afree flowing liquid when the composition is applied, e.g., with a brushor other applicator. The speed at which the network reforms to a gel isa function of particle concentration and the magnitude of the attractiveinteraction between the oppositely charged particles (refer to section“Surface Charge of Particulate Dispersions”). Hyper thixotropiccompositions are particularly useful in foundations, mascaras, haircare, lip compositions, and personal care compositions where lowviscosity is desired during application, yet a rapid increase inviscosity is important to prevent migration of the applied composition.

The term “particle” or “particles” as used herein mean all particlespresent in the compositions of the present invention, including fractalparticles, pigment particles, binders, fillers, and the like, that areinsoluble in the composition.

The term “fractal particles” as used herein refers to geometricparticles of varying fractal dimension or in-built reticulatedstructure; that is, having Hausdorff-Besicovitch dimensions greater thantheir topological dimensions.

The expression “cosmetically acceptable vehicle” refers to a medium thatis compatible with keratin materials such as human skin.

Except where specific examples of actual measured values are presented,numerical values referred to herein should be considered to be qualifiedby the word “about.”

The terms “a” and “an”, as used herein and in the appended claims, mean“one or more” unless otherwise indicated herein.

All percentages and ratios referred to herein are by weight of totalcomposition (i.e., the sum of all components present), unless otherwiseindicated.

Fractal Particles

The first essential component is a gel network having first and secondsubmicron sized fractal particles having opposite surface charges at agiven pH. Referring to FIG. 1, at pH below 7-8, the metal oxides silicaand alumina have opposite surface charge or zeta potential. The first orsecond fractal particles that form the fractal gel most typically havedifferent refractive indices.

The first or second fractal particles that form the fractal gel may eachcomprise two or more different fractal particles having the same charge.The two or more different first (or second) fractal particles of thesame charge may have different sizes, different net surface charges (ofthe same type, however), or different refractive indices.

A brief description of fractal particle geometry follows:

Fractal objects are characterized by a recursive self-similarity. Ingeneral, the fractal nature can be described mathematically by a powerlaw relationship taking the form:

Y=c*X ^(d)  (1)

where c is a constant. Therefore, if data adhere to a power lawrelationship, a plot of log (Y) versus log (X) will yield a straightline with slope d.

Analogously, self-similar fractals, a class of Hausdorff-Besicovitchdimensionality, rely on the object being self-similar at differentlength scales. The power law is consistent with this case following:

A=(1/s)^(D)  (2)

where A is the number of identical parts, s is the reduction factor andD is the self-similar dimension measure of the fractal. Equation 2 canbe arranged as the following

D=log(A)/Log(1/s)  (3)

For example, the sides of a unit square are divided in half, forming 4pieces, therefore A=4, s=½ thus D equals 2. Likewise a SierpinskiGasket, wherein the original triangle side is halved, three trianglepieces are formed. Thus, A=3, s=½ and D=1.5850. Comparatively, considera unit line segment. Dividing the line in half results in 2 equal parts,and so on. Therefore, A=2, s=½ D=1. It is important to note, the valueof D agrees with the topological dimension of the line, yet a line isnot fractal. Accordingly, fractals are those objects wherein theHausdorff-Besicovitch dimension exceeds its topological dimension.

Furthermore, fractals can be classified according to theirself-similarity. There are three basic types of self-similarityexpressed in fractals. Exact self-similarity (the strongest type ofself-similarity). The fractal appears identical at different lengthscales. Fractals of this type are described by displaying exactself-similarity.

Quasi-self-similarity (non-exact form of self-similarity). The fractalappears approximately identical at different length scales.Quasi-self-similar fractals are comprised of distorted and degeneratecopies.

Statistical self-similarity (weakest type of self-similarity). Thefractal is described by statistical measures, which are preserved acrossthe length scale. Random fractals are examples of fractals, which arestatistically self-similar, but not exact or quasi self-similar. Thenature of similarity of fractals can also be described by mathematicalfunctions.

Most fractal objects of interest do not have a readily apparentself-similar nature. Therefore, a convenient method to determine thefractal dimension of the object is the box counting method. This methodis widely used and a direct method to measure the fractal dimensionobjects via image analysis. An object image is projected on a grid ofknown dimensions. Subsequently, the number of blocks that the imagetouches is counted. This data yields the number of blocks (N) and theblock size (reduction factor, s). The grid is resized, and the processis repeated. A plot of the data, where the x-axis is log (s) and they-axis is log (N(s)) using equation 3, yields a slope of value D.

Image analysis is particularly useful to evaluate the fractal dimensionof particulates. Specifically, transmission electron spectroscopy (TEM)is well adapted to evaluate the fractal dimension of complex particulatestructures. Of particular interest are fractal particles that arecomprised of non-overlapping primary particles, which form a largeraggregate structure. Typically, particles of this nature aremanufactured by a fuming process or complex precipitation process.

Evaluation of the mass fractal dimension of particles formed fromaggregates of smaller primary particles involves determination of thenumber of primary particles per aggregate. Typically, this is achievedby evaluating TEM micrographs using digital imaging processingtechniques. The number of primary particles per aggregate (N) isdetermined by dividing the projected area of the aggregate (Aa) by theprojected area of the monomer unit (Am):

N=(Aa/Am)^(α)  (4)

where α is an empirical fitting parameter, typically 1.0-1.1. Therefore,the Hausdorff dimension implies the relationship between the primaryparticle size (dp), the area radius of gyration (Rg), and the number ofprimary particles (N) describes the fractal dimension (Df) of theaggregate:

N=kf(Rg/dp)^(Df)  (5)

where kf is a constant fractal prefactor. A plot of log (N) vs. log (Rg)results in a linear plot of slope Df. Typical Df values for fractalparticles of the present invention obtained by a fuming process rangefrom 1.5-1.9, while fractal particles of the present invention obtainedby a precipitation process range from 2-2.8.

Additional test methods base on rheological measurements and lightscattering measurements can be used to elucidate the dimensionality offractal particles.

The admixture of the first and second fractal particles (hereinafteralso referred to as the positive fractal particles and the negativefractal particles) in a suitable vehicle causes gelation in light ofcharge neutralization of the oppositely charged particles. Moreover, thefractal nature of the particles results in a porous matrix structure,which enhances the ability of the fractal gels of the present inventionto mask wrinkles, lines and other imperfections, which receive alight-weight filling of the fractal network. Because the fractal gel hasa reticulated structure, very little is needed to fill the imperfectionsin the skin. In another embodiment the porous matrix structure of thefractal gel may receive one or more active substances, as hereindescribed.

The size domains and refractive indices of the fractal particles arechosen to effectively fill wrinkles and mask skin imperfections. Thefractal particle network forms an open structure, which provides asurface smoothing effect. Thus, the composition can provide a natural,smooth and youthful appearance with visible reduction in wrinkles andskin imperfections.

Combining aqueous dispersions of each particle type forms a highlystructured gel network as a result of charge neutralization. Typically,the fractal gel may comprise between about 5% to about 75%, preferablyabout 10-40%, most preferably about 20-40% solid fractal particles byweight of the fractal gel. In some instances the particles are providedby the manufacturer as a dispersion. Suitable commercially availablemetal oxide dispersions are Cab-o-Sperse™ PG01, PG063, PG003, PG0042,and AeroDisp™ W1836, W630 supplied by Cabot Corporation and Degussa,respectively. It is also possible to provide nonaqueous dispersions thatcan be used to form a nonaqueous gel phase. Such dispersion media mustbe able to maintain the surface charge of the fractal particle,typically requiring trace quantities of a charge control agent such astetrabutyl ammonium benzoate, so that charge neutralization may occur.Suitable dispersion media that may be used are hydrocarbons such asisododecane, simple esters, and silicone fluids such as cyclomethicone(Ionization of metal oxide surface in non aqueous media: Labib, M. E.;Williams, R. J.; J. Colloid Interface Sci. 1984, 97, 356;

Labib, M. E.; Williams, R. J.; J. Colloid Interface Sci. 1987, 115, 330;Fowkes, et al., “Mechanism of Electric Charging of Particles InNonaqueous Dispersions”, Journal of the American Chemical Society, vol.15, 1982; Fowkes, et al., “Steric And Electrostatic Contributions To TheColloidal Properties of Nonaqueous Dispersions”, Journal of the AmericanChemical Society, vol. 21, 1984; Huang, Y. C., Sanders, N. D., Fowkes,F. M., Lloyd, T. B. “The Impact of Surface Chemistry on ParticleElectrostatic Charging and Viscoelasticity of Precipitated CalciumCarbonate Slurries”. National Institute of Standards and TechnologySpecial Publication 856, USA Department of Commerce, 180-200 (1993)).

Any suitable metal oxide fractal particles or derivatives thereof thatachieve the desired effect may be employed. Preferably, the inorganicnanoparticles particles are fractal metal oxide particles having adiameter of between about 50-300 nm, preferably about 100-250 nm, andmore preferably about 125-200 nm. Diameter as used herein refers to thediameter of a sphere that encompasses the fractal particle. Diameter maybe determined by methods known in the art, e.g., light scattering andTEM. Furthermore, each nanoparticle type has a particle surface areabetween about 50 to 400 m²/g, and more particularly between about 100 to250 m²/g. The fractal dimension of the nanoparticle is below about 2.7,preferably ranges from about 1.2 to 2.5, more preferably from about 1.5to 2.2. Generally, as fractal dimension decreases, the concentration ofsolids in the gel decreases, and as surface area increases, fractaldimension also decreases.

While not common, fractal organic particles are known and can be used inaccordance with the present invention, provided the requisite surfacecharge characteristics are met. For example, organic polyacrylates andtheir derivatives have fractal dimensionality and may be surfacecharged. Preferred organic polyacrylate particles are laurylmethacrylate/dimethyl acrylate crosspolymer (available from Amcol Healthand Beauty Solutions).

The fractal particles may be selected from the group consisting ofsilica, alumina, titania, zirconia, sinc oxide, indium tin oxide, ceria,and mixtures thereof. Particles may be formed as part of a fumingprocess or a precipitation process wherein the metal oxide particle isfractal in dimension. Particles formed by the fuming process arepreferred. Alumina is known to impart high diffuse transmittance, highreflectance, high scattered reflectance and low total reflectance in thevisual spectra, and is a preferred first fractal particle. Silica ispreferred because it has a refractive index that is substantiallymatchable to common cosmetic media, especially silicone oils. As shownin FIG. 1, silica is available with a net surface charge that isopposite to that of alumina at a pH value of most cosmetic formulations,that is, at a pH below about 7-8. Accordingly, silica is a preferredsecond fractal particle, especially when used in conjunction withalumina at a composition pH less than about 7 to 8.

Examples of suitable fractal particles include, but are not limited to,fumed silicas sold by Degussa under the tradename Aerosil, includinghydrophilic and hydrophobic fumed silicas, for example, the AerosilR-900 series, A380™ fumed silica (manufactured by Degussa), OX50™(manufactured by Degussa), colloidal silica such as the Cabosil™ line(manufactured by Cabot), fumed alumina such as SpectrAl™ (manufacturedby Cabot), and fumed titania. Preferred is fumed silica, fumed alumina,fumed titania (Degussa W740X), fumed zirconia (Degussa W2650X, W2550X),fumed ceria (Degussa Adnano), fumed zinc oxide (Degussa Adnano), fumedindium tin oxide (Degussa Adnano) or mixtures thereof.

Cosmetic compositions according to the invention may comprise from about1-100% fractal gel by weight of the cosmetic composition. The broadrange reflects the range of different types of cosmetic products and thevarious product forms; namely, gels, emulsions, and dispersions.Typically, the fractal gel will be at least about 5% and more typicallygreater than 10% fractal gel. Amounts of the gel in the cosmeticcompositions of the invention are also discussed later. Useful fractalgel compositions may include alumina and silica, titania and silica,zirconia and silica, and other combinations of particulates describedwithin.

In a typical embodiment, the weight ratio of alumina to silica is 1:1 to9:1 and is present as a dispersion in water wherein the alumina surfacearea is between 50 to 200 m²/g and the silica surface area is betweenabout 300 to 400 m²/g. Suitable gels can be formed by using Spectral 51or Spectral 80 (Cabot Corporation) fumed alumina and Cab-o-Sil M5,Cab-o-Sil EH-5. FIG. 2 depicts schematically the formation of the gelnetwork from aqueous dispersions SiO₂ and Al₂O₃ particles. In thisdepiction the SiO₂ particles and the Al₂O₃ particles are seen to bespace away from one another in light of the fractal geometry of eachparticle resulting in a highly reticulated structure. Furthermore,dispersions of metal oxides can be chosen based on their surface chargecharacteristics as determined by zeta potential measurements.

Charged particles are subject to electrophoresis, that is to say, in thepresence of an electric field they move with respect to the liquidmedium in which they are dispersed. The region between the particle andthe liquid is known as the plane of shear. The electric potential at theplane of shear is called the zeta potential. The magnitude and sign ofthis potential can be experimentally determined using commerciallyavailable equipment. Typically, to achieve colloidal stability, (i.e.prevent flocculation), charged particulates are required to have aminimum Zeta potential of approximately 25 mV.

Selection of fractal particle pairs can be chosen based on the magnitudeand sign (positive or negative) of the zeta potential at a given pH.Preferably, the magnitude and sign of the zeta potential of eachparticle type is sufficient, such that when combined, a non-settling,semi-rigid gel structure is formed. Preferred dispersions of the firstparticle type have a zeta potential values of about +10 mV to +50 mV,more preferably +10mV to +30 mV, and most preferably +15 mV to +25 mV.Preferred dispersions of the second particle type have a zeta potentialvalues of about −10 mV to −50 mV, more preferably −10mV to −30 mV, andmost preferably −15 mV to −25 mV. Furthermore, evaluation of the pointof zero charge (isoelectric point) of metal oxides is useful topre-select metal oxides of interest, as listed in Table 1.

Surface Charge of Particulate Dispersions

The presence of charge on dispersed colloidal particles occurs by twoprincipal mechanisms: dissociations of ionogenic surface groups orpreferential absorption. Each mechanism can occur simultaneously orindependently. Dissociation of acidic groups on the surface of aparticle will give rise to a negatively charged surface. Conversely,dissociation of basic surface groups will result in a positively chargedsurface. In both cases, the magnitude of the surface charge depends onthe strength of the acidic or basic groups and on the pH of thesolution. The surface charge can be reduced to zero (isoelectric point)by suppressing the surface ionization. This can be achieved bydecreasing the pH in the case of negatively charged particles orincreased the pH in the case of positively charged particles.Furthermore, if alkali is added to a dispersion of negatively chargedparticles, the particles tend to become more negatively charged. If acidis added to this dispersion, then a point will be reached where thecharge on the particle is neutralized. Subsequent addition of acid willcause a build up of positive charge on the particle.

Modification of Surface Charge

Adsorption of ions and ionic surfactants can be specifically adsorbedonto the charged particle surface. In the case of cationic surfactants,adsorption leads to a positively charged surface and in the case ofanionic surfactants, adsorption leads to a negatively charged surface.Adsorption of single valent or multivalent inorganic ions (e.g. Na⁺,Al⁺³) can interact with charged surfaces in one of two ways: reductionof the magnitude of charge at a given pH; change in pH of theisoelectric point (point of neutral charge). The specific adsorption ofions onto a particle surface, even at low concentrations, can have adramatic effect on the surface charge. In some cases, specific ionadsorption can lead to a charge reversal of the surface. The addition ofsurfactants or specific ions to particle dispersions is a common methodto modify the surface charge characteristics.

TABLE 1 Point of Zero Charge (PZC) for Various Oxides in Water Oxide PZCAg₂O 11.2 Al₂0₃ 9.1 BeO 10.2 CdO 11.6 CeO₂ 8.1 CoO 10.2 Co₃O₄ 7.4 Cr₂O₃7.1 CuO 9.3 Fe₂O₃ 8.2 Fe₃O₄ 6.6 HgO 7.3 La₂O₃ 10.1 MgO 12.4 MnO₂ 5.3MoO₃ 2 Nb₂O₅ 2.8 NiO 10.2 PuO₂ 5.3 RuO₂ 9 Sb₂O₅ 1.9 SiO₂ 2 SnO2 5.6Ta₂O₅ 2.8 ThO₂ 9.2 TiO₂ Rutile 5.7 TiO₂ Anatase 6.2 V₂O₃ 8.4 WO₃ 0.4Y₂O₃ 8.9 ZnO 9.2 ZrO₂ 7.6

By way of illustration, referring to FIG. 3, there is shown how therough surface created by wrinkles and fine lines “trap” light, therebyexacerbating topological features. Referring to FIG. 4, the compositionof the present invention fills in fine lines and wrinkles and provide asmooth surface to incident light.

The physical arrangement of the gel structure, high particle loading andnetwork formation, provides a smooth surface for topcoat applications ofany foundation. Referring to FIG. 5, the smoothing gel layer provides ayouthful effect to the skin when used as a primer for pigmentedcosmetics. When light penetrates the smoothing layer, diffuse reflectionthrough the pigmented layer provides a “back lighting” effect,brightening foundations to give a more natural appearance.

The Cosmetic Compositions

The cosmetic compositions of the present invention may be formulated assingle phase aqueous or nonaqueous compositions. Preferably, thecosmetic compositions according to the invention are formulated asemulsions. These emulsions may be oil-in-water (including silicone inwater) emulsions, water-in-oil (including water-in-silicone) emulsions,or multiple emulsions such as oil-in-water-in-oil (o/w/o) orwater-in-oil-in-water (w/o/w), but are preferably silicone-in-wateremulsions. It is understood that the oil phase can comprise siliconeoils, non-silicone organic oils, or mixtures thereof. While notpreferred, the compositions can comprise two immiscible phases that areadmixed at the time of use by shaking.

In addition to the gel phase comprising the fractal particles of thepresent invention, the compositions of the present invention maycomprise one or more active ingredients adapted to bestow a cosmeticbenefit to the skin when applied to the skin as a film and/or one ormore adjuvants or excipients (adjuvants and excipients are collectivelyreferred to herein as adjuvants) to impart to the cosmetic productparticular desirable physical properties, to meet product performancerequirements, or to establish compositional type, e.g., emulsion (of aparticular type), solution, etc. The actives and/or the adjuvants may bepresent in the gel phase, in another phase, or in either, as desired, oras mandated by the chemical system.

Suitable active agents include pigments to impart a color to the skin orother biologic surface; opacifiers and light diffusers; sunscreens; uvlight absorbers; emollients; humectants; occlusive agents; antioxidants;exfoliants; antioxidants; anti-inflammatory agents; skin whiteningagents; abrasives; antiacne agents; hair treatment agents; humectants;emollients; moisturizers; anti-wrinkle ingredients; concealers; mattefinishing agents; proteins; anti-oxidants; bronzers; solvents;ultraviolet (UV) absorbing agents; oil absorbing agents; neutralizingagents. It is understood to those skilled in the art that any othercosmetically acceptable ingredient, i.e., those included in theInternational Cosmetic Ingredient Dictionary and Handbook, 10th ed.(hereinafter INCI) may be used and compatible combinations thereof.

Suitable adjuvants include film forming agents; solvents; viscosity andrheology modifiers such as thickeners; surface active agents includingemulsifiers; hydrotropes; emulsion stabilizers; plasticizers; fillersand bulking agents; pH adjusting agents including buffers, acids, andbases; chelating agents; binders; propellants; fragrances; preservativesand antimicrobials, and compatible combinations thereof.

Suitable active agents and adjuvants used in cosmetic compositions ofthe present invention are tabulated in The International CosmeticIngredient Dictionary and Handbook (commonly INCI) (10th Edition, 2006)(Cosmetic, Toiletries and Fragrance Association). Generally, referenceto specific materials utilizes the INCI adopted name nomenclature. Theactive agents and adjuvants are incorporated in the compositions of thepresent invention in amounts that provide their intended functions, asthose skilled in the cosmetic arts are knowledgeable. Generally, thisamount is from about 0.001 to 25%, more usually 0.01 to 15%, andespecially 0.1 to 10% by weight of the composition.

The cosmetic compositions may contain polymeric light diffusers as knownin the cosmetic arts, such as nylon (e.g., Nylon 12 available from Cabotas SP-500 and Orgasol 2002™), poly(methylacrylic acid) (also known asPMMA or methyl methacrylate crosspolymer; CAS No. 25777-71-3),polyethylene, polystyrene, ethylene/acrylic acid copolymer (e.g., EA-209supplied by Kobo), and fluorinated hydrocarbons such as Teflon. Thepolymeric light diffusers, preferably nylon, are present in aconcentration in the range of between about 0.01-10% preferably about0.1-5% by weight of the composition. Inorganic light diffusers can alsobe used, e.g., boron nitride, barium sulfate, and silicates such ascalcium alumina borosilicate, and are typically present in an amount offrom about 0.01 to about 10%, preferably about 0.1 to about 5% byweight.

The particle content of the cosmetic composition of the presentinvention ranges from about 1-80% solids, preferably about 3-40% solids,more preferably about 5-30% solids. The final dried film as applied tothe skin contains about 1-80% solids, preferably about 5-60% solids,more preferably, about 10-40% solids.

The cosmetic composition of the present invention may contain aviscosity modifier such as a thickener together with emulsifiers tomodify the viscosity of the composition, for example to form creams,pastes, and lotions that enhance skin feel. Suitable viscosity modifiersare starches, cellulose derivatives such as sodium carboxymethylcellulose, methyl cellulose, ethyl cellulose, cationized cellulose,hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethylcellulose; silicates such as veegum or clays; polysaccharides such asxanthan or guar gums, hydrophilic polymers, such as carboxyvinylpolymers, for example carbomers. Viscosity/rheology modifiers may bepresent in the composition in an amount of from about 0.1 to about 10%by weight of the composition.

The cosmetic emulsifier should preferably be an oil-in-water orwater-in-oil emulsifier. Preferably, the oil phase is a silicone oil,and the emulsifier is a silicone emulsifier. Emulsifying agents may bepresent in a concentration of from about 0-10%, preferably about 0.1-6%,more preferably about 3-5%. Nonlimiting examples of suitable emulsifiersare glycerol monostearate, PEG 12 Dimethicone (Dow Corning), RM 2-2051™(Dow Corning), an emulsion of aqueous polyacrylate emulsified intosilicone (dimethicone and cyclopentasiloxane), alkylmethyl siloxanescopolyol (Dow Corning 5200), PEG 11 methylether dimethicone (Shin Etsu),cyclopentasiloxane/PEG/PPG 18/18 dimethicone (Dow Corning 5225C).

The cosmetic composition of the present invention may containnon-occlusive film-forming agents such as, but not limited to, cosmeticfluids, i.e., silicone compounds containing various combinations ofelastomers in a variety of diluents. Examples of suitable cosmeticfluids are cyclopentasiloxane and amino propyldimethicone (Cosmeticfluid 1486-NH) (manufactured by Chemisil), cyclomethicone anddimethicone (Cosmetic fluid 1684-DM) (manufactured by Chemisil), and ablend of low and high viscosity polydimethylsiloxane (e.g. Dow Corning1413 Fluid™) (Dow Corning). Preferred is a blend of high viscositypolydimethylsiloxane in low viscosity polydimethylsiloxane (e.g. DowCorning 1413 Fluid™) (Dow Corning).

In one embodiment the cosmetic composition is nonpigmented.

In a preferred embodiment the cosmetic compositions contain one or morepigments, which are typically present in a different phase from thefractal gel phase. The pigment used herein can be inorganic and/ororganic. Cosmetic compositions according to the invention comprisegreater than or equal to 0.1% pigments by weight of the cosmeticcomposition to provide a pigmenting effect. Preferably, the pigments maybe present from about 0.25% to 15%, most preferably from about 0.1 to10% by weight The pigments are not fractal particles in accordance withthe invention because they do not have the proper size domain, do nothave the proper dimensionality, or are not charged particles. As usedherein the term “pigments” includes lakes, and a single pigment orpigment combinations. Other colorants such as D&C dyes and self-tanningagents such as carbonyl derivatives or food colorants such asdihydroxyacetone (DHA) or erythrulose may be used. Pigments andcolorants are used interchangeably herein.

Preferably, the pigments are selected from the group consisting oftitanium oxides such as rutile titanium dioxide, anatase titaniumdioxide, zinc oxide, zirconium oxide, iron oxides such as ferric oxide,ferrous oxide, yellow iron oxide, red iron oxide, black iron oxide,acylglutamate iron oxides, chromium oxide, chromium hydroxide, bismuthoxy chloride, manganese violet, cerium oxide, ultramarine blue, carmine,and derivatives and mixtures thereof. More preferably, the pigment istitanium oxide, yellow iron oxide, red iron oxide, black iron oxide, andmixtures thereof. The pigments can be surface modified to render themeither hydrophobic or hydrophilic to interact synergistically with thefractal particle network.

The cosmetic composition may also include opacifying agents (pearlescentagents) to add optical shimmer and luster or for tactile silkiness tothe touch such as, but not limited to mica, sericite (a fine grainedvariety of muscovite). These agents may be present in amounts from about0.1-10%, preferably about 0.5-5%.

The cosmetic composition may also include oil phase solvents useful asbase fluids for spreading and lubrication properties or as a vehicle toprovide a medium for one or more of the other constituents of thecosmetic composition. These solvents include water, organic fluids,especially alcohols and hydrocarbon fluids, silicone fluids, hydrophilicand hydrophobic polymers, and the like, and may be present in aconcentration of about 0.5-90%, preferably about 5-50%, most preferably10-35%. Preferred oil phase solvents are cyclomethicones such ascyclotetrasiloxane (e.g. Cyclo-2244 Cosmetic Grade Silicone (D4)(manufactured by Clearco), cyclopentasiloxane (e.g. Cyclo-2245 CosmeticGrade Silicone (D5) (manufactured by Clearco), acyclopentasiloxane/cyclohexasiloxane blend (D5/D6 Blend) Cyclo-2345Cosmetic Grade Silicone (manufactured by Clearco), and acyclomethicone/dimethiconol blend (D5/D4 Blend) Cyclo-1400 CosmeticGrade Silicone (manufactured by Clearco). More preferred is D5.

Water typically is present in amounts ranging from about 10% to about90% water by weight of the composition, preferably from about 40% toabout 80%, and most preferably from about 40% to about 70%. Alsosuitable as aqueous phase solvents are low molecular weight alcoholshaving less than 8 carbons, for example ethanol, propanol, hexanol, andthe like, and polyhydric alcohols, especially glycols. Suitable glycolsare propylene glycol, pentylene glycol, hexylene glycol, and1,2-octanediol. Suitable polyhydric alcohols include sorbitol andglycerin. These may be present in amounts of from about 1% to about 50%,preferably 5% to 35% by weight.

Optionally, electrolytes such as sodium chloride may be added in amountsranging from about 0-5%, preferably from about 0.5-2%.

The compositions of the invention further typically contain an amount ofa pH adjusting agent to provide the desired pH of the composition and atwhich the fractal particles will have the requisite opposite net surfacecharges. Suitable pH adjusting agents are organic and mineral acids asis well known in the cosmetic arts. Buffers to maintain the establishedpH may also be incorporated, for example sodium lactate.

It is further understood that the other cosmetic actives and adjuvantsintroduced into the composition must be of a kind and quantity that arenot detrimental to the advantageous effect which is sought hereinaccording to the invention.

The composition of the present invention improves the optical propertiesof films of cosmetic composition, as compared to those which merelyreflect light producing a shiny appearance, those which merely cover theskin and impart a white cast to the skin, or those which either resultin optical blurring or space filling, but not both. The resultingcomposition when applied to the skin, makes the skin appear moreyouthful, smoother and even in tone.

The cosmetic composition may take on various forms including powder,cake, pencil, stick, ointment, cream, milk, lotion, liquid-phase, gel,emulsion, emulsified gel, mousse, foam, spray, wipes. Preferably, thecosmetic composition is used in a liquid or powder foundation.

The fractal gels may be incorporated in cosmetically acceptablevehicles, such as but not limited to, liquid (e.g. suspension orsolution), gel, emulsion, emulsified gel, mousse, cream, ointment,paste, serum, milk, foam, balm, aerosol, liposomes, solid (e.g. pressedpowders), anhydrous oil and wax composition. Preferably, the cosmeticcomposition is used in a liquid or powder foundation. More specifically,the cosmetic include facial skin care cosmetics such as skin lotion,skin milk, skin cream, gel, and make-ups such as foundation, foundationprimer base, blush, lip stick, eye shadow, eye liner, nail enamel,concealer, mascara, body make-up product, or a sunscreen.

Methods of Use

The methods of use for the cosmetic compositions disclosed and claimedherein concern the improvement in the aesthetic appearance of skin andinclude, but are not limited to: methods of masking one or more ofwrinkles, fine lines, pores, skin imperfections, especially in thefacial, neck or on or around the lip areas; methods to correctimperfections in skin such as blotches, freckles, redness, spider veins,and dark rings around the eyes; methods of enhancing or modifying skincolor; methods to improve finished makeup, and methods for applicationto the hair, eyelashes, and eyebrows.

The compositions of the present invention are suitable for use as a haircosmetic, in particular as a mascara, in light of the unique rheologicalproperties exhibited by the fractal gels, as mentioned above. Thus, thecompositions of the invention are free-flowing under shear, which allowsthem to be applied with a brush or suitable applicator. When the shearis removed the compositions return rapidly to the more viscous gelcondition. Because the compositions are fractal, that is, they areporous, reticulated structures capable of maintaining geometric shape,they are able to coat hair and provide a volumizing benefit.Accordingly, they are ideal as mascaras, especially when formulated witha film former (as previously described), and as hair volumizers fortreating thinning hair.

Examples of facial lines and skin imperfections which can be improvedusing the fractal gels of the present invention include, but are notlimited to; frown lines that run between the eyebrows known as glabellarlines; perioral or smoker's lines which are vertical lines on the mouth;marionette lines at the corner of the mouth known as oral commissures;worry lines that run across the forehead; crow's feet at the corner ofthe eyes known as periorbital lines; deep smile lines that run from theside of the nose to corners of the mouth known as nasolabial furrows;cheek depressions; acne scars; some facial scars; wound or burn scars;keloids; to reduce dark rings around the eyes; to reduce the appearanceof pores or blemishes, age spots, moles, birthmarks; to redefine the lipborder; for artificial or self-tanning, and to reduce skin colorunevenness or dullness.

In one embodiment the fractal gel of the present invention is aspreadable, flowable and greaseless cosmetic composition useful for, butnot limited to, foundation products, finishing powders, blushers,concealers, skin care products, mascara, lip products, and the like. Itcan be incorporated in a skin care or make-up formulation in a quantitysufficient for efficient blurring. In another embodiment, the solidcompositions are substantially gelled to have a solid-likeself-supporting body.

A person skilled in the art can select the appropriate presentationform, and also the method of preparing it, on the basis of generalknowledge, taking into account the nature of the constituents used andthe intended use of the composition.

Facial lines and wrinkles can be present anywhere on the face, and occurmost frequently on the lips and in the eye area. However, it isunderstood by those skilled in the art that the composition can beapplied to any part of the body where a blurring effect is desired suchas to reduce wrinkles, fine lines, pores, and skin imperfections.Non-limiting examples include to conceal imperfections in the skin, suchas to mask the appearance of cellulite or vitiligo, to mask theappearance of spider vessels, moles, age spots, blemishes, acne marksand scars, freckles, birth marks and varicose veins, to conceal damageincurred to the skin as a result of trauma such as cosmetic surgery,burns, stretching of skin, to conceal the appearance of villus hair onthe skin; to provide UV protection to the skin.

The compositions herein can be used by topically applying to the areasof the skin a safe and effective amount of the compositions. Theeffective amount can easily be determined by each user.

As used herein the term, “safe and effective amount” refers to asufficient amount of a compound, composition or other material describedby this phrase to significantly induce a space filling of the appearanceof the skin, but low enough to avoid undue side effects (e.g.,significant skin irritation or sensitization), within the scope of soundjudgment of the skilled person. The safe and effective amount of thecompound, composition or other material may vary with the particularskin being treated, the age and physical condition of the biologicalsubject being treated, the severity of the skin condition, the durationof treatment, the nature of concurrent therapy, the specific compound,composition, or other material employed, the particular cosmeticallyacceptable topical carrier utilized, and the factors within theknowledge and expertise of the skilled person.

The composition can be applied once, twice or more times for severaldays, weeks, months or years at any intervals. The compositions aregenerally applied by light massaging the composition onto the skin.However, the method of application may be any method known in the artand is thus not limited to the aforementioned. Where necessary thecompositions can be removed using soap and water or other cosmeticcleansers.

The invention also relates to a method for therapeutic treatment of theskin. It is further understood that the fractal gel of the presentinvention may be used together with therapeutic agents, together with oradjunctive to pharmaceutical compositions including, but not limited to,anti-acne agents, self-tanning ingredients, anti-inflammatory agents,anti-bacterials, anti-fungals, anti-virals, anti-yeast agents, eyetreatments, analgesics, antidandruff and antiseborrhetic agents,hyperkeratolytics, antipsoriatic agents, skin lightening agents, agents,wound healing agents, burn treatments, tanning agents, hair treatmentagents, hair growth products, wart removers, antipuretics, and hormones.

The fractal gel of the present invention may be used together withcosmetic agents including, but not limited to emollients, sunscreens,age spot treatments, depigmenting agents, anti-aging agents such asexfoliants, anti-glycation endpoint blockers, and the like. Inparticular sunscreens and uv filters are an important cosmetic active inskin care products generally to prevent the harmful rays of the sun fromexacerbating the aging process. These actives are typically present inan amount to provide an SPF value of from 2 to about 50, preferably fromabout 6 to about 30.

A person skilled in the art can select the appropriate presentationform, and also the method of preparing it, on the basis of generalknowledge, taking into account the nature of the constituents used andthe intended use of the composition.

Kits containing the above compositions are also contemplated.Compositions of the present invention can be packaged to contain,separately or in kit form together with a container, instructions orinstruction brochure.

Preparation

The compositions useful for the methods of the present invention aregenerally prepared by conventional methods such as are known in the artof making topical compositions. Such methods typically involve mixing ofthe ingredients in one or more steps to a relatively uniform state, withor without heating, cooling, application of vacuum, and the like.Typically, the fractal gel is made by preparing a dispersion of eachfractal particle in a suitable solvent (dispersant), adjusting thedispersion pH with a pH adjusting agent, and admixing the dispersionswith shear to permit the formation of the gel. In some instances owingto the properties of the constituents it may be necessary to preheat oneor both of the dispersants. The pH adjusting agent may also be providedinto the admixed dispersions rather than into each dispersionindividually. Certain of the adjuvants may require addition as premixeswith a solvent, as generally known in the cosmetic art. The resultinggel can be employed as it is and can itself constitute a skin care ormake-up composition for masking skin imperfections.

Alternatively, the fractal gel may be incorporated into a multiphasecosmetic composition as previously mentioned. The other phase may beprepared in accordance with known methods, for example forming one ormore premixes of the ingredients for combination with the fractal gel.As previously mentioned the polymer in whole or in part may beincorporated into this other phase. Where premixes have been formed atelevated temperatures appropriate cooling of the composition toestablish the emulsion will be necessary.

The following examples describe specific aspects of the invention toillustrate the invention and provide a description of the presentmethods for those skilled in the art. The Examples should not beconstrued as limiting the invention as the examples merely providespecific methodology useful in the understanding and practice of theinvention and its various aspects.

While certain preferred and alternative embodiments of the inventionhave been set forth for purposes of disclosing the invention,modification to the disclosed embodiments can occur to those who areskilled in the art.

EXAMPLES Example 1 Fractal Gel

The following example illustrates the use of combining high and lowsurface area particulates to form a fractal gel network and is notintended to be limiting.

TABLE 2 Dispersion 1 Silica   30% Water 68.6% Glycolic Acid  1.4%Dispersion 2 Alumina   60% Water 38.6% Glycolic Acid  1.4% Silicasupplied by Degussa R380. Alumina supplied by Cabot Spectral A1 51 orSpectral Al 80.

The particle dispersion is made using a high shear mixer equipped with acooling jacket. The water (75% of the total) and glycolic acid wereadded to the mixer. Under high shear, the silica was added slowly. Oncethe silica was added, the dispersion was allowed to mix for 5 minutesunder high shear. Lastly, the remaining 25% of water was added, andallowed to mix for an additional 5 minutes under high shear. Acidity ofthe dispersion was adjusted to pH 4 using basic salts solutions such assodium hydroxide or ammonium hydroxide. Each particle dispersion wasmade in a similar manner. Furthermore, predetermined quantities of eachparticle dispersion were blended using a high-speed mixer to achieve thedesired silica and alumina content of the gel. Once mixed, the resultinggel was subsequently blended with a suitable cosmetic carrier.

Example 2

Table 3 below provides examples of cosmetic compositions of the fractalparticle gels incorporated into an oil-in-water emulsion.

TABLE 3 Typical non-pigmented and pigmented cosmetic compositions I IIIII VI V VI VII 1 Alumina¹ 12.0 13.3 7.5 27.0 24.0 21.0 12.0 2 Silica²3.0 6.7 7.5 1.5 3.0 4.5 3.0 3 Demineralized Water qs 100% qs 100% qs100% qs 100% qs 100% qs 100% qs 100% 4 PPG-1 Isoceteth-3 acetate 4.3 3.64.3 4.3 4.3 4.3 4.3 5 Octyldodecyl neopenanoate 2.2 1.8 2.2 2.2 2.1 2.22.2 6 Glyceral stearate/PEG-75 2.4 2.1 2.4 2.4 2.4 2.4 2.4 stearate 7Steareth-2 0.8 0.7 0.8 0.8 0.8 0.8 0.8 8 Glyceral monostearate-NS 1.31.1 1.3 1.4 1.3 1.4 1.3 emulsifier 9 Isocetyl stearate 3.5 2.9 3.5 3.53.4 3.5 3.5 10 C12-C15 alcohol benzoate 3.0 2.6 3.0 3.0 3.0 3.0 3.0 11Cyclomethicone pentamer 5.4 4.6 5.4 5.4 5.4 5.4 4.4 12 Dimethicone 50 ct2.7 2.3 2.7 2.2 2.1 2.2 2.7 13 Dimethiconol 0.5 0.5 0.5 0.5 0.5 0.5 0.514 Dimethicon-polysilicone- 0.7 0.6 0.7 0.7 0.7 0.7 0.7 1/PET 15Dimethyl polysiloxane 2.2 1.8 2.2 1.9 1.9 0.3 1.2 16 ChromalitePigments⁴ 5.0 footnotes ¹Cabot Spectral A1 ²Degussa R380 ⁴Engelhardbismuth oxy chloride

The formulations of Examples I to VII for Table 3 are prepared asfollows: the constituents are mixed together in accordance with theprocedures set forth below.

Oil-in-water emulsions are formed in the following manner. Aqueouscomponents are placed in a 1 liter beaker and subsequently heated to120° F. using a hot plate. A homogenizer (Silverson L4RT) equipped witha high speed homogenization head (¾ tubular type impeller using anemulsifier screen) is used to mix the aqueous composition at 3600 rpm.The components of the oil phase are added in a separate 1 liter beakerand thoroughly mixed prior to adding to the aqueous composition. The oilphase is added slowly under high shear mixing (greater than 5000 rpm)and allowed to mix for 30 minutes once at 120° F. The emulsion isallowed to cool to room temperature under low shear, 3000 rpm. Oncecool, the emulsion composition is mixed under low shear, 200-400 rpmwith the fractal particle gel in pre-determined quantities. Theresulting make-up composition is then ready for packaging.

1. A cosmetic composition for application to a biologic substratewherein said composition comprises, in a nonaqueous medium, a firstfractal particle and a second fractal particle, wherein said first andsecond fractal particles interact with one another to form a gelnetwork.
 2. The cosmetic composition according to claim 1, wherein saidfractal particles have a diameter of between about 50-300 nm.
 3. Thecosmetic composition according to claim 2, wherein said fractalparticles have a diameter of between about 100-250 nm.
 4. The cosmeticcomposition according to claim 1, wherein said fractal particles aremetal oxide particles selected from the group consisting of fumedsilica, fumed alumina, fumed titania, fumed zirconia, fumed ceria, fumedzinc oxide, fumed indium tin oxide, and mixtures thereof.
 5. Thecosmetic composition according to claim 1, wherein said fractalparticles comprise from about 5% to about 80% by weight of thecomposition.
 6. The cosmetic composition according to claim 1, furthercomprising one or more polymeric light diffusing agents selected fromthe group consisting of nylon, poly(methyl acrylic acid), boron nitride,barium sulfate, polyethylene, polystyrene, ethylene/acrylic acidcopolymer, fluorinated hydrocarbons, silicates and silicone, andmixtures and derivatives thereof.
 7. The cosmetic composition accordingto claim 1, comprising a particle content of about 1% to about 85%solids by weight of the composition.
 8. The cosmetic compositionaccording to claim 7, comprising a particle content of about 10% toabout 40% solids by weight of the composition.
 9. The cosmeticcomposition according to claim 1, further comprising a film formingagent.
 10. The cosmetic composition according to claim 9, wherein saidfilm forming agent is selected from the group consisting ofcyclopentasiloxane and amino propyldimethicone, cyclomethicone anddimethicone, and a blend of low and high viscosity polydimethylsiloxane.11. The cosmetic composition according to claim 1, further comprising apigment.
 12. A method for concealing imperfections in human skin,comprising applying to said skin an effective amount of a cosmeticcomposition comprising in a nonaqueous medium, a first fractal particleand a second fractal particle, wherein said first and second fractalparticles interact with one another to form a gel network.
 13. Themethod according to claim 12, further comprising a step of applying afoundation on top of said composition.